# Lesson Plan — 3 × 90 minutes

## Session A — Light cones as causal maps (IK-1, IK-3, IK-9)
- (10') Opening story + preconceptions quick poll.
- (20') Mini-lesson: spacetime & mixed-signature interval; light cones as boundary.
- (25') Guided reading of Diagram 1; classify A/B/C (IK-1).
- (20') Pair task WS-A (everyday examples of time-/light-/space-like).
- (15') Exit narrative (100–150 words) — causally consistent (IK-3, IK-9).

## Session B — Worldlines, proper time, geodesics (IK-2, IK-4, IK-5, IK-8)
- (15') Recap via peer instruction Q1–Q3.
- (25') Mini-lesson: reading slope & curvature; proper time as "worn watch".
- (25') WS-D/WS-E (compare two worldlines → qualitative proper time).
- (15') Micro-lab: draw your day as a worldline (low-tech allowed).
- (10') Reflection card (RC) — what can/cannot be known from this event?

## Session C — Spacelike slices Σ & agency (IK-6, IK-7)
- (15') Demo: move Σ across Diagram 2; identify P_A, P_B.
- (25') WS-H (argue: "now" is frame-relative; causal class is invariant).
- (25') WS-I (map past/future cones for a decision scenario).
- (15') Peer instruction Q7–Q10.
- (10') Wrap-up & post reflection.
